There is considerable interest regarding the formation of carbon-carbon bonds via olefin metathesis. Olefin metathesis refers to the metal-catalysed redistribution of carbon-carbon double bonds. Cross metathesis (CM) can be described as a metathesis reaction between two non-cyclic olefins, which may be the same or different, for example:
Where the olefins are the same, the reaction is known as self metathesis.
Ring-opening metathesis polymerization (ROMP) is a variant of olefin metathesis reactions wherein cyclic olefins (for example) produce polymers and co-polymers, for example:

Ring-closing metathesis (RCM) represents a process in which an acyclic diene (for example) is cyclised to produce a cycloalkene, for example;

As indicated above metathesis reactions take place in the presence of a catalyst. A great deal of research has been done in an attempt to synthesise and isolate catalysts which are able to catalyse homogeneous olefin metathesis reactions. More particularly the synthesis of Group VIII transition metal metathesis catalysts has led to catalysts with increased functional group tolerance and stability with respect to conditions such as air, water and acids.
During the 1990's the so-called “1st generation Grubbs catalyst” of formula 1a was developed:
where Cy is cyclohexyl.
This well defined ruthenium catalyst afforded high selectivities, high reaction rates and good tolerance for oxygenates in feed during homogeneous olefin metathesis reactions, including cross metathesis, ring closing metathesis and ring opening metathesis polymerisation. These processes have many potential commercial applications for the commodities, pharmaceutical and fine chemicals industries as well as in the field of speciality polymers. Several reviews describe the development and applications of Grubbs-type catalysts (for example Acc. Chem. Res. 2001, 34, 18-24; Angew. Chem., Int. Ed., 2000, 39, 3012-3043).
Much research has been carried out to investigate the effect of changing the nature of the ligands, (for example J. Am. Chem. Soc. 1997, 119, 3887-3897; Tetrahedron Lett. 1999, 40, 2247-2250; Angew. Chem., Int. Ed. 1998, 37, 2490-2493) resulting in the development of second generation Grubbs catalysts. The main thrust of second generation Grubbs catalyst research has related to a move away from the use of phosphine ligands to the use of highly nucleophilic N-heterocyclic carbenes for homogeneous metathesis reactions. Formula 1b shows the structure of the standard second generation Grubbs catalyst. While this catalyst shows greater reactivity compared to catalyst 1a, it is more expensive than the first generation catalyst.
where Cy=cyclohexyl, and Mes=mesityl
WO ZA03/00087 discloses the use of a phosphorus containing ligand as a ligand for a metathesis catalyst in a catalysed metathesis reaction wherein the phosphorus containing ligand is a heterocyclic organic compound with a ligating phosphorus atom as an atom in the heterocyclic ring structure of the heterocyclic organic compound.
A major disadvantage of complexes depicted by formula 1a relates to their preparation which requires either reagents which are hazardous (e.g. potentially explosive diazoalkanes), or difficult to prepare (e.g. diphenylcyclopropene), or extremely sensitive.
As a result there exists a need to develop efficient routes to these complexes where                1. The individual components (ligands and alkylidene) are inexpensive, non-hazardous and scaleable        2. The reaction to prepare the Ru-alkylidene-type olefin metathesis catalyst that uses the individual components as reagents is straight-forward, non-hazardous and can be performed on the multi-kilogram scale economically.        
It has now been found that relatively inexpensive phosphorus containing ligands such as phosphabicylononane ligands, when combined with a specific alkylidene-type moiety such as the indenylidene alkylidene moiety provide a non-hazardous, economical Ru-alkylidene-type olefin metathesis catalysts. These catalysts or catalyst precursors are usually easy to prepare from well accessible, stable and essentially non-toxic starting materials and can usually be isolated and stored. At least some of these catalysts exhibit high catalytic activity, a good compatibility with functional groups, solvents, water and additives, and they need not to be activated by any additive.
An indenylidene ruthenium complex was first synthesized by Hill (J. Chem. Soc., Dalton Trans. 1999, 285), who incorrectly assigned the structure of the diphenylallenylidene complex. Together with Fürstner the complex was used in various ring-closing metathesis reactions (Chem. Commun. 1999, 601-602). Later detailed evaluations showed that the correct structure is the rearranged indenylidene complex (Organometallics 1999, 18, 5416-5419, Chem. Eur. J. 2001, 7, 4811-4820). Still, this complex was only used in RCM by Fürstner in the synthesis of natural products.
In 2003 F. Verpoort published the use of this complex in the Atom Transfer Radical Addition (ATRA), New J. Chem. 2003, 27, 257-262. Several different olefins have been used in the ATRA with carbon tetrachloride in good to nearly quantitative yields. Verpoort also used the complex in the nucleophilic addition of carboxylic acids to terminal alkynes (Synlett 2002, 935-941), e.g. formic acid, acetic acid, isovaleric acid, or benzoic acid to t-Butylacetylene, 1,7-octadiyne or 4-pentynoic acid. Here the catalyst showed moderate yields. Blechert (Synlett 2001, 3, 430-432) used the catalyst as a precursor for other metathesis catalysts.
The indenylidene complexes as described above did not include a phosphorus containing ligand which is a heterocyclic organic compound with a ligating phosphorous atom as an atom in the heterocyclic ring structure of the heterocyclic organic compound.